Comment by quotedmycode

Two are quickbooks and freshbooks. You really should study accounting if you've never seen discounts tied to the date paid. Cash flow is important to every business, and a lot of businesses do give discounts for quick payment.

http://www.freshbooks.com/blog/the-best-invoice-payment-term...

https://www.americanexpress.com/us/small-business/openforum/...

Being able to define your payment terms is important.